---
config:
  theme: neo
---
graph TD
    A[开始] -->  B[输入账号和密码]
    B --> |a| C{账号和密码是否正确?}
    C -->|b 是| D[登录成功]
    C -->|c 否| E[提示账号或密码错误]
    D --> F[结束]
    E --> F
